Set your oven to 350°F (175°C) so it can fully preheat. Coat a 10-inch Bundt pan well with butter or nonstick baking spray, making sure to cover every groove and the center tube. Sprinkle a light layer of flour over the pan if you like, then tap out any excess to help the cake come out cleanly after baking.

Add the cake mix, sugar, baking soda, salt, and instant pudding mix to a large bowl. Give the dry ingredients a quick stir so everything is evenly combined. Crack in the eggs, pour in the vegetable oil and Mountain Dew, then mix for 2 to 3 minutes until the batter looks silky, smooth, and completely blended.

Transfer the batter into the prepared Bundt pan and spread it into an even layer. Place it in the oven and bake for 40 to 45 minutes, or until a toothpick inserted into the center comes out clean. Remove the pan from the oven and let the cake cool for 10 to 15 minutes before carefully turning it onto a wire rack to finish cooling.

Combine the powdered sugar, Mountain Dew, vanilla extract, and fresh lemon juice in a medium bowl. Whisk until the mixture is smooth and glossy. If the glaze is thicker than you’d like, add a teaspoon of soda at a time. If it becomes too thin, whisk in a little more powdered sugar until it pours easily.

After the cake has cooled completely, spoon the glaze over the top, letting it drip naturally around the sides. Leave the cake for about 15 minutes so the glaze can set before slicing. Enjoy each piece on its own, or serve it alongside whipped cream, fresh berries, or a scoop of vanilla ice cream for an extra-special dessert.